The first step in verifying the environment is to run Emscripten with the version command (-v). The command prints out information about the toolchain and runs some basic sanity tests to check that the required tools are available.

At this point you need to Install and activate any missing components. When everything is set up properly, ./emcc-v should give no warnings, and if you just enter ./emcc (without any input files), it should only give the following warning:

Missing tools can often be added using the Emscripten SDK (emsdk). For example, to fix a warning that Java is missing, locate it in the repository, install it, and then set it as active:

#List all the components. Look for the missing component (in this case "java-7.45-64bit")./emsdklist#Install the missing component./emsdkinstalljava-7.45-64bit#Set the component as active./emsdkactivatejava-7.45-64bit